function o(object,f){
	object.background="images/dh_bg2.gif";
	f.style.color="#FFFFFF";
}
function c(object,f){
	object.background="";
	f.style.color="#000080";
}
//改变图片大小   
function resizepic(thispic)   
{   
if(thispic.width>550){thispic.height=thispic.height*550/thispic.width;thispic.width=550;}    
}   
//无级缩放图片大小   
function bbimg(o)   
{   
  var zoom=parseInt(o.style.zoom, 10)||100;   
  zoom+=event.wheelDelta/12;   
  if (zoom>0) o.style.zoom=zoom+'%';   
  return false;   
}   
//双击鼠标滚动屏幕的代码   
var currentpos,timer;   
function initialize()   
{   
timer=setInterval ("scrollwindow ()",30);   
}   
function sc()   
{   
clearInterval(timer);   
}   
function scrollwindow()   
{   
currentpos=document.body.scrollTop;   
window.scroll(0,++currentpos);   
if (currentpos !=document.body.scrollTop)   
sc();   
}   
document.onmousedown=sc   
document.ondblclick=initialize